Hey everyone, so I was working on problem that resulted in this: y=√4-x^2 ( the 4-x^2 is under the square root) and I was stumped as to what to do next... then later finally giving up, I realized that that was the end of the problem, and that it would just end in either negative or positive. This isn't the first time something like this has happened. How do you know when you're done working on a problem? Often times, I'd think I was done with a problem, and I had simplified is as low as possible, but then whamo! I was supposed to factor it, or do something else to it... How do you know if you've reached the end, or if there is more to do?